What many people think is among the most dangerous intersections in Harford County might be best explained this way:

When an Aegis photographer went to shoot the intersection of Grafton Shop Road and Route 23 in Forest Hill for this story on Monday afternoon, he witnessed a minor accident.

On Thursday, a three-vehicle accident at the same intersection claimed the fourth life in the last 10 years and second in less than eight months. In addition to the lives lost, there have been other accidents at the corner, some involving serious injuries, according to various published accounts over the years.

Already this year, there have been four accidents at the intersection, including the one Monday and the fatal Thursday.

From an engineering and historical perspective, however, the intersection, which is controlled only by stop signs on Grafton Shop Road, doesn't warrant a traffic light, according for a spokesman for the State Highway Administration, which has authority over Route 23.

Following the last fatal accident at the corner in July 2012, the SHA conducted a signal study in November that concluded the past number of crashes and other factors, such as sight lines and recent development, "did not come close," to justifying installing a signal, SHA spokesman Dave Buck said Tuesday.

In Thursday's accident, a 58-year-old Churchville woman, Deborah Wimborough, died when the SUV in which she was a passenger was clipped by a small pickup truck and then rammed by a fuel truck. The driver of the SUV, Mary Niles, 51, of Street, was flown to the Maryland Shock Trauma Center in Baltimore in serious condition and remained hospitalized. The driver and a passenger in the fuel truck, which was hauling kerosene, were taken to Upper Chesapeake Medical Center in Bel Air with non-life threatening injuries.

In the preliminary investigation, Maryland State Police from the Bel Air Barrack said the pickup, driven by Bradley Baker, 23, of Fallston, was headed south on Grafton Shop and was stopped at the stop sign waiting to cross Route 23. Baker told troopers he couldn't see the oncoming SUV because of the sun and when he tried to cross Route 23, he hit the SUV on its left side, causing it to spin counter-clockwise into the path of an oncoming kerosene truck, driven by Charles Chew, 46, of York, Pa., and also occupied by Ralph Davis III. The kerosene truck broadsided the SUV on the passenger side, killing Mrs. Wimborough, police said.

A horse trailer that was being towed by the SUV became disconnected during the accident. The two horses inside were cared for at the scene by Harford County Animal Control personnel and a local vet, police said. One horse was seriously injured and later had to be euthanized, according to Debbie Sullivan, who was asked to care for the animals at her farm near Jarrettsville. The other, a pony, was also injured and has been cared for and returned to the owner, Sullivan said Wednesday.

Police listed obstruction of vision, either by the sun or lights, as well as Baker's failure to yield the right-of-way and failure to pay full time and attention as factors contributing to the crash, according to a State Police accident report.

Last July 27, Margaret Mary Campbell, a 79-year-old Bel Air resident, died as a result of a two-car accident around 10:30 a.m. at the intersection of Grafton Shop Road and Route 23, according to State Police.

Mrs. Campbell was headed south on Grafton Shop Road in a 2005 Ford Focus, approaching the Route 23 intersection, when she failed to yield the right-of-way to a 2005 Ford pickup, driven by David John Jockel, 57, of Fallston, traveling west on Route 23. State Police said the Focus was broadsided by the pickup in the intersection. Mrs. Campbell was flown to shock trauma, where she later died.

Prior to Mrs. Campbell's death, there had been no fatalities at Grafton Shop and Route 23 since September 2003 when Regina L. Szcetanski, 25, of Lutherville, was killed along with Damon G. Scott, 6, of Baltimore. Ms. Szcetanski allegedly ran a stop sign on Grafton Shop Road and was struck broadside by a vehicle traveling on Route 23.

Police and many motorists have long been wary about the conditions at the intersection, where Grafton Shop, a two-lane, narrow road with a 30 mph speed limit serving a number of new housing developments in a triangle of Bel Air, Forest Hill and Fallston, intersects with Route 23, a wide and straight two-lane highway with a 50 mph speed limit.

Buck, of the SHA, said there were 15 crashes at the intersection from 2009 through 2012, fewer than four a year. He acknowledged last July's fatality prompted the agency to study the intersection, but based on the statistics and the state and national criteria, SHA engineers concluded a light wasn't needed.

Whenever there is a horrific accident like last week's, emotions tend to run particularly high, which is understandable, Buck said, noting that the SHA has to judge the conditions from an engineering perspective, not an emotional one.

Buck said more than 90 percent of the crashes on state highways are caused by driver error, which he said appeared to be the case both with last week's fatal accident and the one at Grafton Shop and Route 23 last July.

He also noted that over the years the SHA has added wider shoulders and right turn lanes from Route 23 to Grafton Shop and the county has done the same on Grafton Shop, the most recent turn lane being installed last fall.

Beyond that, however, he said the agency has no additional upgrades or safety measures planned.

Admitting he's not an engineer, Seipp said that he thinks, from a police perspective, a roundabout at the intersection would decrease drivers' speed, just as it did along the stretch of Route 23 between Routes 24 and 1 when an entrance was built to the Forest Hill Airpark.

He said drivers typically are either in a hurry and don't look both ways before starting to cross Route 23, or they have poor depth perception when it comes to how far away a car really is. He also said cars tend to drive rather fast along that stretch.

Besides the four accidents there so far this year, he said there were seven at the intersection in 2012 (including the July fatality) and four in 2011.

Even before last week's fatal accident, Maryland State Police had stepped up traffic enforcement in the area, and has done so even more since Thursday, First Sgt. Steve Seipp of the Bel Air Barrack said Tuesday. Troopers are trying to slow down traffic through the area, he said.

"It's one of the roads we target," Seipp said.

This story has been updated with newer information about condition of the two horses that were in a trailer being towed by one of the vehicles involved in last week's fatal accident.